1. Field of the Invention:
The present invention relates generally to a heat-pipe type solar collector, and more particularly to an integral heat-pipe type solar collector utilizing a heat pipe as a heat conducting element.
2. Description of the Prior Art:
Using a heat pipe as a heat transfer element can quickly transfer the solar energy collected by a heat collector to a water tank, which improves the problem of slow heat transfer in conventional solar collectors that rely on natural cyclical transfer of heat.
Both U.S. Pat. No. 4,416,261 to van der Aa and U.S. Pat. No. 4,067,315 to Mahdjuri teach solar collectors. In U.S. Pat. No. 4,421,100 to Yu, a thermosyphon heat pipe hot water appliance is disclosed. In U.S. Pat. No. 4,438,759 to Kitajima et al., a heat-pipe type solar collector is described. In these prior art devices, the solar heat collected by the heat absorber portion is transferred by upper connecting tubes to the heat release portion pre-disposed in the water tank. Heat is transferred to the water in the water tank by means of heat exchange.
In prior heat-pipe type solar collectors, the higher the heat collection efficiency of the heat collector pipes is, the better the heat dissipation effects thereof. When there is not much sunlight, especially after sunset, the heat collector pipes will lose considerable heat energy so that the temperature of water in the tank drops as a result of reverse flow of heat. Therefore, it is very necessary to have a design that can maintain the temperature of the water in the tank. At present, the usual method is to coat the outer wall of the water tank with a heat insulating material. But the effect is limited. Besides, the heat insulating effect of the material will decrease with time. Furthermore, although the method of using natural convection may cause the fluid in the heat release portion to flow, the speed is very slow, and the efficiency is consequently low.